In general, dental hospitals or the like have performed medical cures and treatments to patients' affected parts through impression taking that prepares plaster casts for the patients' teeth. However, in the impression taking process, there have been problems, e.g., consumption of materials, cross-infection, possibility of damage to prepared casts, and preservation difficulties.
As a conventional method widely used to see the state of a patient's oral cavity, there has been a method of inserting a sheet-shaped film into the patient's oral cavity, fixing the film in the proximity of the patient's affected part by using the patient's hand or tongue, projecting a radiation ray such as an X-ray onto the affected part of the oral cavity, and using the film obtained from the projection.
However, since the conventional method depends on measurement through two-dimensional manual works using radiographs, or computer tomography (CT), errors may occur in the process of two-dimensional plane measurement of a three-dimensional structure. Further, a large amount of radiation rays are projected to a patient. Patients would have a financial burden. Complicated trial stages may cause various critical problems.
Accordingly, there has been a demand for an intra-oral scanner, which reduces the possibility of causing any problems in patients' physical conditions and exactly accomplishes three-dimensional modeling of patients' teeth.